beginning to recuperate at this nato base. they were beaten, tied up and saw their colleagues executed. the survivors are shocked and shaken. >> it happened so fast. >> reporter: they witnessed horrifying scenes and had to walk past their dead colleagues' bodies. and one foreigner was used as bait to lure his co-workers out before being shot. steven mcfall had his mouth taped and had to wear explosives strapped to his chest. others like mark grant hid for more than 80 hours and survived by scrambling up on the roof or locked themselves inside their rooms. >> we barricaded together in one of the offices, we lock the door and we put a desk on the door. we did a barricade. >> reporter: when they finally got out, joy and relief. >> when the guys who picked us up, the rescue guys were wonderful. we were like long lost friends. >> reporter: one survivor's family says they have been through hell this week. his son says he was up all night crying. when he heard his father was alive, it was the best news he'd ever heard. dan? >> nick schifrin, thank you. bianna, over to you. >> terrifying week.